Repairing tree bark?

When the builder of our new house was clearing land he damaged the bark on two
rather large oak trees. Is there a way I can prevent the trees from further
damage by repairing or protecting the bark? In both cases the damaged areas are
approximately 1 sq ft in size.
Someone I know suggested putting roofing cement over the damaged areas to
prevent water from getting under the bark and causing more damage.
I normally don't read this news group, so please send mail to me directly. I'll
post a summary if necessary.
Thanks, Marty
marty at sw.stratus.com